Floating roof



Feb. 13, 1951 F. L. GoLDsBY ET AL FLOATING RooF Filed Feb. 6, 1946Patented Feb. 13, 1951 FLOATING ROOF Fred L. Goldsby and Clifford M.Orr, Chicago, Ill., assignors to Chicago Bridge & Iron Company, acorporation of Illinois Application February 6, 1946, Serial No. 645,867

(Cl. E20-26) 7 claims. l

'I'his invention relates to a iioating roof for use in a floating rooftank.

Floating roof tanks are used for storing volatile liquids. In thesetanks the roof floats on top of the liquid and rises and falls as thequantity of liquid is increased and decreased. Various types of floatingroofs have been proposed in the past for use in tanks of this type. Manyci the roofs, however, were too heavy or difcult to construct, and somewould not maintain themselves level on the surface of the liquid,especially when subjected to loads of rain water, snow, and the like, orto the pressure of wind.

We have invented a floating roof that is relatively light-weight andthat maintains its level on top of the liquid at all times. The new rooffunctions efficiently even under a load of snow, and provisions are madefor draining water from the roof, even in cases of very heavy rainfall.The new floating roof comprises a deck, a subn stantially centrallylocated pontoon beneath said deck, and radial pontoons also beneath saiddeck extending from the central pontoon.

The invention will be described as related to the embodiment shown inthe accompanying drawings. Of the drawings Fig. l is a plan view,partially broken away for clarity of illustration, of a floating rooftank employing the new floating roof; and Fig. 2 is a vertical sectiontaken along line 2--2 of Fig. 1.

The floating roof tank comprises an outer substantially cylindricalshell IS and a floating roof I I therein adapted to float on top of thecontents of the tank. The floating roof is positioned within the shelland has a narrow space I2 between the edge of the roof and the shell.Any type sealing means (not shown) may be used between the roof and theshell.

The oating roof Il has a deck I3 essentially flat but sloping slightlydownwardly toward the center. Around the edge of the deck there is i-,cated a vertical rim I4 extending above and below the deck. Beneath thedeck I3 there are located a central pontoon I 5 and radial pontoons I6with the radial pontoons being substantially evenly spaced around theroof and extending from the central pontoon I5 to the rim I4. As showneach radial pontoon I5 is of substantially triangular shape with theapex being adjacent the central pontoon I5. Adjacent sides II ofadjacent pontoons are substantially parallel and the central pontoon I5is formed of partitions IS con necting the apex of one radial pontoon tothe next apex.

In the center of the roof there is provided a 2 drain I9 extending fromthe lowest portion of the deck I3 through the central pontoon I5. AnyWater that falls on the deck will run to the center of the deck and bedrawn oli through the drain ln the iioating roof as shown any vaporsformed will gather under the deck I3 and will form a substantiallyannular vapor space 2n around the outer edge of the deck. Escape of thevapors will be prevented by the downwardly extending portion of the rimI4.

In order to equalize vapor pressure within the vapor spaces 20 betweenpontoons I6 a substantially horizontal pipe ZI is provided extendingthrough each pontoon and communicatingr with the vapor spaces under thedeck of the roof ad jacent the pontoon. The pipes have their outletsnear the decks so as to be in communication with the vapor as soon asformed. Such pipes are not absolutely necessary but are preferred inorder that the roof will float level at all times.

Having described our invention as shown in the accompanying drawings, itis our intention that the invention be not limited by any of the detailsof the description unless otherwise specified, but rather be construedbroadly within its spirit and scope as set out in the accompanyingclaims.

We claim:

l. A heating roof for a floating roof tank comprising a deck slopingtoward the center, a een trai polygonal pontoon beneath the deck, adrain at substantially the center of the roof and extending through thecentral pontoon, a depending rim at the outer edge of the deck, and aplurality of substantially evenly spaced triangular pontoons beneath thedeck extending rom the central pontoon to the rirn, the apex of each ofsaid triangular pontoons being at one of the apices of the centralpontoon, adjacent sides of adjacent triangular pontoons being parallelto each other and being widely spaced to provide a substantial vaporspace therebetween.

2. The floating roof of claim 1 wherein a vapor passageway is providedextending through each pontoon and communicating with the vapor spaceson either side oi said pontoon.

3. A oating roof for a iioating roof tank comprlsing a circular,substantially at throughout the top thereof, single deck slopingslightly toward the center, a depending peripheral rim at the outer edgeof the deck, means forming with said deck a centrally located pontoontherebeu neath, and means forming with said deck spaced pontoonstherebeneath radiating outwardly from the central pontoon to the rimwith the portions 3 of the deck between the last mentioned pontoonsforming gas retaining spaces beneath the deck.

4. The floating roof of claim 3 Wherein there is provided a drain atsubstantially the center eX- tending through the central pontoon.

5. The floating roof of claim 3 wherein the radial pontoolns aretriangular and are substantially equally spaced around the roof,adjacent sides of adjacent pontoons being substantially parallel to eachother.

6. The floating roof of claim 3 in which the central pontoon ispolygonal and the radial pontoons are triangular with the apexV of eachtriangle at one of the apioes of the polygon.

7. The floating roof of claim 3 in which adja- 15 cent sides of adjacentradial pontoons are substantially parallel to each other.

FRED L. GOLDSBY. CLIFFORD M. ORR.

4 REFERENCES CITED The following references are of record in the ille ofthis patent:

UNITED STATES PATENTS Number Name Date 1,665,163 Gallagher Apr. 3, 19281,777,560 Griin Oct. 7, 1930 2,089,645 Diekmann Aug. 10, 1937 2,282,772Wiggins May 12, 1942 2,287,213 Wiggins June 23, 1942 2,359,416 HammerenOct. 3, 1944 2,464,786 Allen Mar. 22. 1949

